Good Lord. Purdey, nor Mr. Beesley ever intended the gun to be opened upside down for any reason...but the mechanism did have to open, cock and eject all in the same motion and to do that...it had to be able to open forcefully, so forcefully that the gun could do it all even if turned upside down. They were trying to market the gun as the only true self opener at the time and the gun functioning correctly upside down was a showmanship & marketing sort of thing. I bet a few of us have watches that are water resistant to 50m or deeper.....not that any of you goofs are EVER going to test that out anytime soon either. :-)